Spaced repetition schedule calculator: the date and length of every review
Published · Updated · by the Paced team
| Pass | When | Length |
|---|---|---|
| D0 | Day 0 (the first study) | 2 h 30 |
| D+1 | Day 1 | 45 min |
| D+3 | Day 3 | 39 min |
| D+7 | Day 7 | 33 min |
| D+15 | Day 15 | 27 min |
| D+30 | Day 30 | 21 min |
| D+60 | Day 60 | 15 min |
| D+120 | Day 120 | 15 min |
| D+240 | Day 240 | 15 min |
Weekly load if you add topics every week
Each topic is 2 h 30 on the first day and brings its own reviews on the pace above. Weekly budget: 18 h (3 h × 6 days). 12 weeks shown.
| Week | New study | Reviews | Total | Fits? |
|---|---|---|---|---|
| 1 | 10 h | 4 h 57 | 14 h 57 | yes |
| 2 | 10 h | 7 h 48 | 17 h 48 | yes |
| 3 | 10 h | 9 h 36 | 19 h 36 | over by 1 h 36 |
| 4 | 10 h | 9 h 36 | 19 h 36 | over by 1 h 36 |
| 5 | 10 h | 11 h | 21 h | over by 3 h |
| 6 | 10 h | 11 h | 21 h | over by 3 h |
| 7 | 10 h | 11 h | 21 h | over by 3 h |
| 8 | 10 h | 11 h | 21 h | over by 3 h |
| 9 | 10 h | 11 h 30 | 21 h 30 | over by 3 h 30 |
| 10 | 10 h | 12 h | 22 h | over by 4 h |
| 11 | 10 h | 12 h | 22 h | over by 4 h |
| 12 | 10 h | 12 h | 22 h | over by 4 h |
The plan stops fitting in week 3: fewer topics a week, shorter first studies, a lighter pace, or more hours. Peak: week 10, 22 h. Reviews that land on a day off are counted in that week: a real planner moves them to the next study day.
How to read the result
- Pass and date. D0 is the first study; D+1, D+3… are the reviews, counted in days after it. On the Standard pace a 2 h 30 topic comes back 8 times over 240 days and costs 3 h 30 of reviews in total.
- Length. Each review is shorter than the one before: a review is a recall, not a re-study. If a review regularly takes longer than planned, the topic is too big, or the first study was too short.
- After the exam. A review that lands after the exam date is still useful for long-term memory, but it does nothing for that exam. Either tighten the pace (Intensive, or a custom list that ends before the date) or start the topic earlier.
- Weekly load. New topics are only part of the week; the reviews of earlier weeks are the rest, and they grow until the oldest topics reach their last pass. The table shows the week it stops fitting your budget.
A worked example
4 new topics a week, 2 h 30 each, Standard pace, six study days of three hours (18 h a week). The first week is all new study; by week 10 the reviews reach 12 h and the week totals 22 h. The plan stops fitting in week 3, with 19 h 36 of work for 18 h of budget. Same inputs as the defaults above; change one and watch the table move.
| Week | New study | Reviews | Total | Budget 18 h |
|---|---|---|---|---|
| 1 | 10 h | 4 h 57 | 14 h 57 | fits |
| 2 | 10 h | 7 h 48 | 17 h 48 | fits |
| 3 | 10 h | 9 h 36 | 19 h 36 | over by 1 h 36 |
| 4 | 10 h | 9 h 36 | 19 h 36 | over by 1 h 36 |
| 5 | 10 h | 11 h | 21 h | over by 3 h |
| 6 | 10 h | 11 h | 21 h | over by 3 h |
| 7 | 10 h | 11 h | 21 h | over by 3 h |
| 8 | 10 h | 11 h | 21 h | over by 3 h |
| 9 | 10 h | 11 h 30 | 21 h 30 | over by 3 h 30 |
| 10 | 10 h | 12 h | 22 h | over by 4 h |
| 11 | 10 h | 12 h | 22 h | over by 4 h |
| 12 | 10 h | 12 h | 22 h | over by 4 h |
What the research behind the paces says
Spreading reviews out beats massing them: in a meta-analysis of 317 experiments, the gap that maximised retention grew with the time until the test (Cepeda et al., 2006), and in a study of more than 1,350 learners the best gap was a shrinking share of the test delay as that delay grew (Cepeda et al., 2008). With flashcards, spacing beat cramming for 90% of participants, yet most of them believed cramming had worked better (Kornell, 2009). A review of ten study techniques rated distributed practice and practice testing as the two of high utility (Dunlosky et al., 2013); among 324 undergraduates, scheduling one's study and self-testing went with higher grades (Hartwig & Dunlosky, 2012). None of these studies prescribes one sequence of days: the paces above are practical choices consistent with them, and the calculator exists because the hard part is fitting the reviews into a real week.
The calculator shows one topic, or a steady intake, on a blank calendar. Paced does the same for every topic you add, inside the hours left by your classes, shifts and days off, moves the reviews that fall on a day off, and tells you when a plan will not fit, up to 90 days ahead.
New to the method? Start with which intervals and why, then how to turn them into a timetable.
Questions
How does the calculator choose the review dates?
It adds each pace's days to your first-study date. The Standard pace is D0, D+1, D+3, D+7, D+15, D+30, D+60, D+120, D+240; Light and Intensive are the other two built-in paces of Paced, and Custom takes your own days (1 to 400, twelve passes at most). The dates are plain calendar arithmetic, not a prediction of your memory.
Where do the review durations come from?
From the default curve of Paced: the first review takes 30% of the first study's length, each later one 4 points less, never under 10%, and never under 5 minutes. They are starting estimates; in the app the Debrief and the timer replace them with what your sessions really take.
Which pace should I pick before an exam?
The closer the exam, the shorter the gaps. In Cepeda and colleagues' 2008 study the best gap was about 20 to 40% of the time to the test when the test came a week later, and about 5 to 10% when it came a year later. Enter your exam date: the calculator flags every review that would land after it.
What does the weekly load table assume?
That you add the same number of topics every week, each as long as the first-study length above, spread over your study days, and that every review is done on its day. It is our arithmetic on your inputs, not a measurement; a real planner also moves the reviews that fall on a day off.
Is anything I type saved or sent?
No. The calculator runs in your browser, keeps nothing between visits and sends nothing anywhere. The Copy button only writes the schedule to your clipboard.
Sources
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380. Meta-analysis of 839 assessments in 317 experiments: the gap that maximises retention grows with how long you need to remember.
- Cepeda, N. J., Vul, E., Rohrer, D., Wixted, J. T., & Pashler, H. (2008). Spacing effects in learning: A temporal ridgeline of optimal retention. Psychological Science, 19(11), 1095–1102. More than 1,350 learners, review gaps up to 3.5 months, final tests up to a year later.
- Kornell, N. (2009). Optimising learning using flashcards: Spacing is more effective than cramming. Applied Cognitive Psychology, 23(9), 1297–1317. Three experiments with flashcards: spacing beat massing for 90% of participants, yet 72% believed massing had worked better.
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4–58. Review of 10 techniques: practice testing and distributed practice rated high utility; rereading and highlighting low.
- Hartwig, M. K., & Dunlosky, J. (2012). Study strategies of college students: Are self-testing and scheduling related to achievement?. Psychonomic Bulletin & Review, 19(1), 126–134. Survey of 324 undergraduates: self-testing and scheduling were associated with GPA; low performers studied late at night more often and all students were driven by deadlines.